JP2014169914A - Signal quality evaluation device and evaluation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To notify an evaluator of a deviation of a measurement value from a normal range when the measurement value in the midst of averaging deviates from the normal range in a signal quality evaluation device performing appropriateness determination to a result in which the measurement value calculated from waveform data on a signal of an evaluation object is averaged, and to enable an analysis of the waveform data in this case.SOLUTION: A signal quality evaluation device is configured to: acquire waveform data on a signal Sx of an evaluation object, and sequentially update the acquired waveform data, and store the updated waveform data in a waveform data memory 22; calculate a measurement value as to a predetermined measurement item with respect to the newly stored waveform data; perform an averaging process to the calculated measurement value by a preliminarily set number of averaging times, and determine whether each of calculated measurement values falls within a first normal range, and whether a final measurement result obtained by the averaging process falls within a second normal range; store the waveform data serving as a base of the measurement value determined not to fall within the first normal range in an NG waveform data memory 28; and perform a detail analysis process to the stored waveform data.

Description

  According to the present invention, predetermined processing is performed to acquire waveform data (time axis waveform or frequency axis waveform) of various signals used for communication or the like and perform measurement on predetermined items for the acquired waveform data. It relates to signal evaluation technology that repeats a number of times, averages the measured values, and makes a pass / fail judgment on the measurement results obtained by the averaged processing, and particularly the measured values in the middle of the averaging processing deviate from the normal range. The present invention relates to a technique for making it possible to easily identify the cause of an error.

  Standards for the quality of the signals output by devices that use public communication networks are established, and the quality of the signals output by these devices is pre-determined in the development and repair departments of such devices. A quality evaluation apparatus that determines whether or not a predetermined standard is satisfied is required.

  This type of quality evaluation apparatus acquires waveform data of a signal output by a test object, and performs measurement items (measurement relating to level, measurement relating to frequency, measurement relating to modulation quality, etc.) predetermined for the waveform data. The measurement is performed, and the pass / fail judgment is made by comparing the measurement result with a preset standard value.

  As described above, for example, Patent Document 1 discloses a technique for acquiring data of a signal to be evaluated, performing predetermined measurement, and determining the quality of the measurement result.

Japanese Patent Laid-Open No. 10-221387

  The technique of Patent Document 1 relates to a spectrum analyzer, and performs pass / fail judgment for spurious levels appearing in spectrum waveform data obtained by frequency sweeping. The center frequency of a digital modulation signal, modulation error ratio MER, In the measurement of error vector amplitude EVM and the like, quality evaluation is rarely performed only with values obtained by performing calculation processing on waveform data acquired for evaluation once, and averaging processing is performed a certain number of times on measurement values, In many cases, the pass / fail determination is performed on the averaged measurement result.

  In addition, as a process commonly performed by spectrum analyzers, spectrum waveform data in the same frequency range is continuously acquired multiple times, and this is averaged to remove random noise components. Although spectrum waveform data is obtained and is not particularly described in Patent Document 1, it is necessary to perform an averaging process on the spectrum waveform data so that the level of spurious can be accurately grasped without being influenced by noise.

  As described above, in the apparatus that acquires the waveform data of the signal and evaluates the quality thereof, the averaging process is generally performed on the measurement result, and the quality determination is performed on the averaged result. It is the current situation.

  In a system that requires a large number of times of averaging (for example, several tens to several hundreds), measurement is performed while updating previously acquired waveform data with newly acquired waveform data in order to suppress a large amount of memory consumption. Therefore, the following problems arise.

  That is, when the measurement value deviates from the normal range during the averaging process, even if the final measurement result enters the abnormal range and the abnormality is determined, the measurement value deviating from the normal range is obtained. No waveform data remains, and the cause of the abnormality determination cannot be specified.

  Even if the measured value deviates from the normal range, for example, in the + direction and enters the abnormal range in the middle of the averaging process, the number of deviations is smaller than the average number or the deviation in the-direction is the same. If it occurs at a low frequency, the final measurement result by the averaging process enters the normal range and is judged normal, and the evaluator does not even know that the measurement value has changed to the abnormal range.

  The present invention solves the above problems and allows the evaluator to confirm that the measured value has deviated from the normal range during the averaging process, even when performing a pass / fail determination on the averaged result. It is another object of the present invention to provide a signal quality evaluation apparatus and an evaluation method that can easily identify and analyze the waveform data as the basis.

In order to achieve the above object, a signal quality evaluation apparatus according to claim 1 of the present invention provides:
A waveform data memory (22) for storing waveform data of a signal to be evaluated;
A waveform data acquisition unit (21) for sequentially acquiring waveform data for a predetermined time of a signal to be evaluated, and sequentially updating and storing the newly acquired waveform data in the waveform data memory;
Each time new waveform data is stored in the waveform data memory, the waveform data is read and subjected to predetermined calculation processing, and a measurement calculation processing section (23) for sequentially calculating measurement values for predetermined measurement items;
An averaging processing unit (24) that performs an averaging process for a predetermined number of averaging times on the measurement values sequentially calculated by the measurement calculation processing unit;
A first determination processing unit (25) for determining whether or not the measurement values sequentially calculated by the measurement calculation processing unit are in a first normal range;
A second determination processing unit (26) for determining whether or not a final measurement result obtained by the averaging process for the averaging number by the averaging processing unit is in a second normal range;
An NG waveform data memory (28) for storing waveform data on which abnormal measurement values are based;
An NG waveform data storage unit that reads out waveform data from the waveform data memory and stores it in the NG waveform data memory, based on the measurement value determined not to be in the first normal range by the first determination processing unit (27) and
An indicator (30);
A determination result display unit (29) for displaying the determination results of the first determination process and the second determination process on the display;
An NG waveform data analysis unit (31) for performing an analysis process on the waveform data stored in the NG waveform data memory.

The signal quality table method according to claim 2 of the present invention is:
Sequentially acquiring waveform data for a predetermined time of a signal to be evaluated, and sequentially updating and storing the acquired new waveform data in a waveform data memory;
Performing predetermined arithmetic processing on the waveform data newly stored in the waveform data memory, and calculating a measurement value for a predetermined measurement item;
Performing an averaging process for a predetermined number of averaging times on the calculated measurement value;
A first determination step of determining whether or not the calculated measurement value is in a first normal range;
A second determination step of determining whether or not the final measurement result obtained by the averaging process is in a second normal range;
Reading out waveform data from the waveform data memory as a basis for the measurement value determined not in the first normal range in the first determination step, and storing the waveform data in an NG waveform data memory;
Displaying the determination results of the first determination stage and the second determination stage;
Analyzing the waveform data stored in the NG waveform data memory.

  As described above, in the present invention, waveform data for a predetermined time of a signal to be evaluated is sequentially acquired, the acquired new waveform data is sequentially updated and stored in the waveform data memory, and is newly stored in the waveform data memory. A predetermined calculation process is performed on the measured waveform data, a measurement value for a predetermined measurement item is calculated, and an averaging process is performed on the calculated measurement value for a preset number of averaging times and calculation is performed. It is determined whether or not the measured value is in the first normal range and whether the final measurement result obtained by the averaging process is in the second normal range, and is not in the first normal range. The waveform data that is the basis of the determined measurement value is stored in the NG waveform data memory, the determination result is also displayed together with the final determination result, and the analysis process for the waveform data stored in the NG waveform data memory is performed. It has become playable way.

  Therefore, the evaluator can confirm that the measured value has deviated from the normal range during the averaging process, and the waveform data that is the basis thereof can be easily identified and analyzed.

Configuration diagram of an embodiment of the present invention Display example of processing results of the embodiment Display example of processing results of the embodiment Display example of processing results of the embodiment The flowchart which shows an example of the process sequence of embodiment

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a configuration of a signal quality evaluation apparatus 20 to which the present invention is applied.

  The signal quality evaluation apparatus 20 includes a waveform data acquisition unit 21, a waveform data memory 22, a measurement calculation processing unit 23, an averaging processing unit 24, a first determination processing unit 25, a second determination processing unit 26, and NG waveform data. A storage unit 27, an NG waveform data memory 28, a determination result display unit 29, a display 30, and an NG waveform data analysis unit 31 are provided.

  The waveform data acquisition unit 21 receives the signal Sx to be evaluated for a predetermined period, samples it at a predetermined sampling period, converts it into digital waveform data, and temporarily stores the series of waveform data in the waveform data memory 22. . This process is repeated at least at an averaging number N (for example, 500 times) described later at a predetermined time interval, and the old waveform data in the waveform data memory 22 is updated with new waveform data each time.

  Here, if the signal Sx is, for example, a high-frequency signal, the waveform data acquisition unit 21 performs A / D conversion processing after converting the signal Sx to a low frequency band that can be A / D converted by frequency conversion processing. If the signal Sx is a digital modulation signal, an IQ two-phase digital signal is generated and output by orthogonal demodulation processing.

  Each time new waveform data is written in the waveform data memory 22, the measurement calculation processing unit 23 reads the new waveform data, performs calculation processing on a measurement item designated in advance, and obtains a measurement value for each measurement item.

  For example, when the signal Sx to be evaluated is a digital modulation signal, its power, EVM (error vector amplitude), center frequency shift, etc. are used as measurement items, and calculation processing necessary for these measurements is performed.

  Hereinafter, these measurement items are A, B, and C, and the measurement values are a (i), b (i), and c (i) (i is the number of measurement times).

  The measurement values a (i), b (i), and c (i) obtained by the measurement calculation processing unit 23 are input to the averaging processing unit 24 and the first determination processing unit 25.

  Each time the measurement calculation processing unit 23 obtains a new measurement value, the averaging processing unit 24 performs an averaging process N times designated in advance for the measurement value.

  That is, the first measurement values a (1), b (1), c (1) are temporarily stored in the internal memory as initial values of the average values Ava, AVb, AVc, and the next measurement values a (2), b At the stage where (2) and c (2) are obtained, the value of the internal memory is updated with the addition result of the new measurement value and the stored value of the internal memory as follows.

[AVa + a (2)] / 2 → AVa
[AVb + b (2)] / 2 → AVb
[AVc + c (2)] / 2 → AVc

  Similarly, even when the next measurement values a (3), b (3), and c (3) are obtained, the result of addition of these new measurement values and the stored value of the internal memory is as follows. Update the internal memory value.

[AVa + a (3)] / 2 → AVa
[AVb + b (3)] / 2 → AVb
[AVc + c (3)] / 2 → AVc

  The averaging processing unit 24 repeats the above process N times to obtain an averaged final measurement result for each measurement item.

  On the other hand, the first determination processing unit 25 determines whether or not each measurement value a (i) to c (i) is in the first normal range (Ha, Hb, Hc) determined in advance for each measurement item. Determine whether. In addition, the second determination processing unit 26 uses a second normal range (Ha ′, Hb ′, preliminarily determined for each measurement item) with respect to the final measurement results AVa to AVc obtained by the averaging processing unit 24. Hc ′) is determined. The first normal range and the second normal range may be the same, and the first normal range may be set wider than the second normal range.

  In this signal quality evaluation apparatus 20, a normal mode, an NG through mode, and an NG stop mode can be designated for each measurement item.

  In the normal mode, the determination by the first determination processing unit 25 is not performed for each measurement value, and only the determination by the second determination processing unit 26 is performed on the N average values (final measurement results).

  Further, in the NG through mode, the first determination processing unit 25 performs determination on each measurement value, but even if an NG determination is issued in each determination, the measurement is continued and the second determination is performed. In this mode, the determination is also made for the average value (final value) of N times by the processing unit 26. However, the evaluator is notified by the determination result display unit 29 described later that the first determination processing unit 25 has made an NG determination in the middle of averaging.

  Further, in the NG stop mode, the first determination processing unit 25 makes a determination on each measurement value, and stops the measurement when an NG determination is issued. Also in this case, the evaluator is notified by the determination result display unit 29 that NG has occurred during the averaging process.

  These can be set according to the property of the measurement item. For example, the measurement item A, in which variation for each measurement is not important, is the normal mode, and for the measurement item B, in which both the variation for each measurement and the final measurement result are problems, the NG through mode, and the variation in each measurement value is a problem. For the measurement item C, the NG stop mode is set.

  When the NG determination is made by the first determination processing unit 25, the NG waveform data storage unit 27 reads out the waveform data that causes the NG determination from the waveform data memory 22, and the NG determined measurement items and measurement results And the like are stored in the NG waveform data memory 28.

  The determination result display unit 29 completes N averaging processes by the averaging processing unit 24 while the first determination processing unit 25 does not make an NG determination for the measurement item set in the NG stop mode. When the determination result by the second determination processing unit 26 for the final measurement result is obtained, the determination result of the first determination processing unit 25 and the determination result of the second determination processing unit 26 are displayed on the display 30. In addition, the determination result is displayed even when the first determination processing unit 25 issues an NG determination for the measurement item set to the NG stop mode. However, in this case, since the final measurement result subjected to the averaging process is not obtained, the provisional determination results of the first determination processing unit 25 and the second determination processing unit 26 at that time are displayed. It will be.

  FIG. 2 shows a display example when the averaging process N times for the three measurement items A to C is completed. The final measurement results AVa to AVc for the measurement items A to C and the corresponding results are shown. Final determination results OK, NG, and OK are displayed. In addition, the mode designated for each measurement item is displayed, the NG through mode is designated, and the measurement item B for which the final measurement result is also NG determination is the individual determination result by the first determination processing unit 25. “With NG” is displayed.

  FIG. 3 also shows a display example when N times of averaging processes for three measurement items A to C are completed, and the final measurement results AVa to AVc for each measurement item A to C and those. The determination results OK, OK, and OK are displayed. In this case, “NO” is displayed as the individual determination result by the first determination processing unit 25 for the measurement item B whose final measurement result is OK determination.

  From the display of FIG. 2 and FIG. 3, for the measurement item designated in the NG through mode, NG determination is made in the middle of the averaging process, regardless of whether the determination on the final measurement result averaged is NG or OK. The evaluator can surely grasp that there was a measured value.

  The NG waveform data analysis unit 31 reads the waveform data, measurement results, and the like stored in the NG waveform data memory 28, causes the waveform data that is determined to be NG to be displayed on the display 30, for example, and performs FFT processing or the like, for example. The function is executed to perform more detailed analysis, and the waveform data and detailed analysis results are displayed.

  Here, the NG waveform data analysis unit 31 clicks the display portion of “NG” in FIGS. 2 and 3, for example, by operating an operation unit (not shown) such as a pointing device such as a mouse, thereby The waveform data stored in the memory 28 is read out and displayed together with the measured values as shown in FIG. Further, functions F1 to F3 (for example, FFT processing) that can be executed on the waveform data are displayed, and those functions are selected and executed, thereby enabling more detailed analysis on the displayed waveform data. In this example, NG determination is performed five times for the measurement item B, one of the waveform data and the measurement value b (j) are displayed, and another waveform for which NG determination is made by operating the cursor next to the measurement value. Data can be read and displayed. The display in FIGS. 2 to 4 is an example, and these display forms are arbitrary.

  In FIG. 1, the function of the signal quality table device 20 is shown as a block, but FIG. 5 shows an example of the processing procedure of the signal quality table device 20 of the embodiment. The processing procedure will be described below with reference to this figure.

  First, the measurement count instruction value n is initialized to 1, the waveform data of the signal to be evaluated is acquired, and updated and stored in the waveform data memory 22 (S1).

  Next, the waveform data newly stored in the waveform data memory 22 is read out, a calculation process is performed for a predetermined measurement item, and a first normal range is used for the measurement value obtained by the calculation process. (S3, S4).

  In this first determination process, if there is no NG determination in the measurement item other than the normal mode, an averaging process is performed for each measurement value, n is incremented by 1 and the process returns to process S2, and the next waveform data is obtained. The process of obtaining is repeated until n reaches N (S5 to S8).

  Then, when the number of measurements reaches N without an NG determination in the first determination process, a second determination process using the second normal range for the final measurement result obtained by averaging N times The determination result and the first determination result are displayed on the display 30 (S9, S10). In this case, since no NG determination has been made in the first determination process, all the individual determination results in the display example shown in FIG. 3 are NG, but in the case where an NG determination has occurred as described later, the evaluator When the operation for instructing the analysis is performed, the NG waveform data stored in the NG waveform data memory 28 is read out and displayed as shown in FIG. 4, and the analysis can be performed (S11, S12).

  On the other hand, when the NG determination is made in the first determination process in the middle of the averaging process in the process S5, when the measurement item is only the NG through mode, the waveform data at that time is stored in the NG waveform data memory 28. The data is saved, and the process returns to the averaging process (S6), and the measurement is continued (S13, S14).

  When the measurement item for which NG determination is made in the first determination processing is not only the NG through mode, that is, when the NG stop mode is included, the waveform data at that time is stored in the NG waveform data memory 28. Then, the measurement is interrupted, the process proceeds to the determination result display (S10), and a display indicating that the measurement value has deviated from the first normal range is performed for the measurement item designated in the NG stop mode. In this case, for example, the final measurement result and the second determination result of each measurement item in FIG. 2 and FIG. 3 are set as the plank, and the individual determination result for the measurement item designated in the NG stop mode is NG. That's fine.

  As described above, the signal quality evaluation device 20 according to the embodiment does not depend on the second determination result with respect to the averaged measurement result, but the waveform when the NG determination is made in the first determination for each measurement value. Since the data is stored and the first determination result is displayed, the evaluator can surely determine whether or not the NG determination is made for each measurement value and the factor thereof without depending on the final determination result.

  DESCRIPTION OF SYMBOLS 20 ... Signal quality evaluation apparatus, 21 ... Waveform data acquisition means, 22 ... Waveform data memory, 23 ... Measurement calculation process part, 24 ... Averaging process part, 25 ... 1st determination process part, 26 ...... Second determination processing unit, 27 NG waveform data storage unit, 28 NG waveform data memory, 29 Judgment result display unit, 30 …… Display unit, 31 NG waveform data analysis unit

Claims (2)

A waveform data memory (22) for storing waveform data of a signal to be evaluated;
A waveform data acquisition unit (21) for sequentially acquiring waveform data for a predetermined time of a signal to be evaluated, and sequentially updating and storing the newly acquired waveform data in the waveform data memory;
Each time new waveform data is stored in the waveform data memory, the waveform data is read and subjected to predetermined calculation processing, and a measurement calculation processing section (23) for sequentially calculating measurement values for predetermined measurement items;
An averaging processing unit (24) that performs an averaging process for a predetermined number of averaging times on the measurement values sequentially calculated by the measurement calculation processing unit;
A first determination processing unit (25) for determining whether or not the measurement values sequentially calculated by the measurement calculation processing unit are in a first normal range;
A second determination processing unit (26) for determining whether or not a final measurement result obtained by the averaging process for the averaging number by the averaging processing unit is in a second normal range;
An NG waveform data memory (28) for storing waveform data on which abnormal measurement values are based;
An NG waveform data storage unit that reads out waveform data from the waveform data memory and stores it in the NG waveform data memory, based on the measurement value determined not to be in the first normal range by the first determination processing unit (27) and
An indicator (30);
A determination result display unit (29) for displaying the determination results of the first determination process and the second determination process on the display;
A signal quality evaluation apparatus comprising: an NG waveform data analysis unit (31) for performing an analysis process on the waveform data stored in the NG waveform data memory. Sequentially acquiring waveform data for a predetermined time of a signal to be evaluated, and sequentially updating and storing the acquired new waveform data in a waveform data memory;
Performing predetermined arithmetic processing on the waveform data newly stored in the waveform data memory, and calculating a measurement value for a predetermined measurement item;
Performing an averaging process for a predetermined number of averaging times on the calculated measurement value;
A first determination step of determining whether or not the calculated measurement value is in a first normal range;
A second determination step of determining whether or not the final measurement result obtained by the averaging process is in a second normal range;
Reading out waveform data from the waveform data memory as a basis for the measurement value determined not in the first normal range in the first determination step, and storing the waveform data in an NG waveform data memory;
Displaying the determination results of the first determination stage and the second determination stage;
And a step of performing an analysis process on the waveform data stored in the NG waveform data memory.

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